The present invention relates to a regulator for diving and more particularly to such a regulator suitable to be used as a regulator usually referred to as a second stage.
A regulator for diving is well known, which comprises a basic structure adapted to be kept in air-tight condition so long as a diver is using it, a built-in pressure-controllable air supply mechanism provided in the basic structure, a mouthpiece connected to the basic structure and a check valve mounted on the basic structure so as to be switched between its opened and closed positions. The air supply mechanism comprises a housing connected to an air supply source provided externally of the basic structure, a pressure regulating valve and a valve seal against and from which the pressure regulating valve is pressed or disengaged, wherein the valve seal is formed on an end of a sleeve telescopically mounted in a tubular portion of the housing.
With such a regulator of prior art, there is an O-ring between the sleeve and the tubular portion of the housing in order that possible leak of the air within the basic structure may be effectively prevented. Such leak-proof measure necessarily requires that the sleeve should be held in close contact with the inner surface of the tubular portion, so it is often difficult to insert or withdraw the sleeve into or from the tubular portion. Operation of inserting or withdrawing the sleeve may sometimes damage the valve seal and the sleeve may be exchanged with a fresh one. Furthermore, the end of the sleeve may be sometimes worked to have a sharp edge in order to improve a more close contact between the valve and the valve seal. If such sharp-edged end is left in close contact with the valve made of flexible elastic material for a long period of time, tightness at which these two elements are kept in close contact with each other may unacceptably increase. As a result, it is apprehended that the valve might be prevented from smoothly operating.
It is an object of the present invention to improve an above-cited regulator of prior art so that the sleeve having the valve seal may be easily inserted or withdrawn into or from the housing and the valve may be smoothly disengaged from the valve seal.
According to the present invention, there is provided a regulator for diving comprising a basic structure adapted to be kept in substantially air-tight condition so long as a diver is actually using it, a pressure-controllable air supply mechanism provided in the basic structure to supply the diver with air, a mouthpiece connected to the basic structure and a check valve provided in the basic structure so as to be switched between opened and closed positions.
The air supply mechanism has further a tubular housing connected to an air supply source provided externally of the basic structure, a pressure reducing valve provided in the housing and a valve seal provided in the housing so that the pressure reducing valve can be pressed against and disengaged from this valve seal, wherein the valve is formed on the end of the sleeve which lies in the housing as the sleeve is inserted into and withdrawn from the housing and the opposite end of the sleeve is formed on its inner surface with threads.
The present invention includes such preferred embodiments as follows:
The sleeve and the housing are pressed against each other with an O-ring interposed between them.
The surface of the valve is permanently treated in order that the pressure reducing valve may be easily pressed against and disengaged from the valve seal.